Thank you all very much for your advice concerning setting up a
recording volume. Everything works like a charm now!

As far as recording itselfs is concerned, I have no difficulty to
record. In recording screen just press rec or play button and
recording starts. Pressing rec button while recording will continue
recording in a new file. Pressing play button while recording will
pause it. Long press of play button will stop recording and if it is
stopped, will exit a recording screen.